The present invention relates to a top loading staple cassette that has a top piece removable engaged with the top opening of the cover on the base member and staples are inserted from a top of the cassette.
A conventional staple cassette 10 for staplers is disclosed in FIGS. 1 and 2, and generally includes a base member 12 having two side walls 122 on a top thereof and a plurality of connection protrusions 121 extend laterally from two sides of the base member 12. A cover 11 has two side walls and a close top, and a plurality of holes 111 are defined through the side walls of the cover 11 so that the cover 11 may be mounted to the base member 12 with the two side walls 122 of the base member 12 located inside of the two side walls of the cover 11, and the protrusions 121 engaged with the holes 111. A slot 113 is defined through an end of the close top of the cover 11 so that a pushing plate (not shown) connected to an arm of the stapler is movably inserted in the slot 113. A cap 14 includes a rod 141 which is connected to a head 142. Two lugs 144 extend from a side of the head 142 and each of which has a hook 143 on an outside thereof The hooks 143 are engaged with positioning holes 112 defined in the two side walls of the cover 11. A spring 15 is mounted to the rod 141 and a pushing member 13 has a connection port 132 which is connected to a distal end of the spring 15 so that the staples 123 mounted across the two side walls 122 are urged by the two sides 131 of the pushing member 13.
When reloading the staples 123, the cover 11 is disengaged from the base member 12 and put a stack of staples 123 across the two side walls 122. The cover 11 is then engaged with the base member 12 again. Nevertheless, because the spring 15 applies a force to the head 142 so that the hooks 143 could disengage from the positioning holes 112. Once the head 142 is disengaged from the cover 11, the spring 15 will bounce away and the user has to spend a lot of time to find it back. Therefore, the manufacturers firmly engage the hooks 143 with the positioning holes 112, once the staples are completely empty, a new set of cassette with pre-loaded staples is replaced. Obviously, this is not an ideal way to used because the whole set of the base member 12 and the cover 11 with the cap 14 are discarded every time replacing a new stack of staples.
The present invention intends to provide a staple cassette wherein the staples can be re-loaded from a top opening of the cassette without pivoting the cover.
In accordance with one aspect of the present invention, there is provided a staple cassette for staplers and the cassette comprises a base member having two side walls and two flanges extend from two sides of the base member. A first hook extends from an underside of the base member and is located close to a first end of the base member. An opening is defined through the underside of the base member and located close to a second end of the base member.
A pushing member is movably mounted onto the two side walls of the base member and has a second hook extending from an underside of the top. A spring has a first end hooked to the first hook on the base member and a second end of the spring extends through the opening and is engaged with the second hook on the pushing member.
A cover is mounted to the base member and includes a top and two side walls. A slot is defined through the top of the cover and an opening is defined through the top of the cover. The two side walls of the base member are located between the two side walls of the cover. A top piece is slidably engaged with the opening.